![Paul Mackerras](/assets/img/avatar_default.png)
This adds code which gives us the option on ppc64 of instantiating the PCI tree (the tree of pci_bus and pci_dev structs) from the Open Firmware device tree rather than by probing PCI configuration space. The OF device tree has a node for each PCI device and bridge in the system, with properties that tell us what addresses the firmware has configured for them and other details. There are a couple of reasons why this is needed. First, on systems with a hypervisor, there is a PCI-PCI bridge per slot under the PCI host bridges. These PCI-PCI bridges have special isolation features for virtualization. We can't write to their config space, and we are not supposed to be reading their config space either. The firmware tells us about the address ranges that they pass in the OF device tree. Secondly, on powermacs, the interrupt controller is in a PCI device that may be behind a PCI-PCI bridge. If we happened to take an interrupt just at the point when the device or a bridge on the path to it was disabled for probing, we would crash when we try to access the interrupt controller. I have implemented a platform-specific function which is called for each PCI bridge (host or PCI-PCI) to say whether the code should look in the device tree or use normal PCI probing for the devices under that bridge. On pSeries machines we use the device tree if we're running under a hypervisor, otherwise we use normal probing. On powermacs we use normal probing for the AGP bridge, since the device for the AGP bridge itself isn't shown in the device tree (at least on my G5), and the device tree for everything else. This has been tested on a dual G5 powermac, a partition on a POWER5 machine (running under the hypervisor), and a legacy iSeries partition. Signed-off-by: Paul Mackerras <paulus@samba.org>
129 lines
3.7 KiB
C
129 lines
3.7 KiB
C
#ifdef __KERNEL__
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#ifndef _ASM_PCI_BRIDGE_H
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#define _ASM_PCI_BRIDGE_H
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#include <linux/pci.h>
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/*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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/*
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* Structure of a PCI controller (host bridge)
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*/
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struct pci_controller {
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struct pci_bus *bus;
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char is_dynamic;
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void *arch_data;
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struct list_head list_node;
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int first_busno;
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int last_busno;
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void __iomem *io_base_virt;
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unsigned long io_base_phys;
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/* Some machines have a non 1:1 mapping of
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* the PCI memory space in the CPU bus space
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*/
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unsigned long pci_mem_offset;
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unsigned long pci_io_size;
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struct pci_ops *ops;
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volatile unsigned int __iomem *cfg_addr;
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volatile unsigned char __iomem *cfg_data;
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/* Currently, we limit ourselves to 1 IO range and 3 mem
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* ranges since the common pci_bus structure can't handle more
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*/
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struct resource io_resource;
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struct resource mem_resources[3];
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int global_number;
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int local_number;
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unsigned long buid;
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unsigned long dma_window_base_cur;
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unsigned long dma_window_size;
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};
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/*
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* PCI stuff, for nodes representing PCI devices, pointed to
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* by device_node->data.
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*/
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struct pci_controller;
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struct iommu_table;
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struct pci_dn {
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int busno; /* for pci devices */
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int bussubno; /* for pci devices */
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int devfn; /* for pci devices */
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int eeh_mode; /* See eeh.h for possible EEH_MODEs */
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int eeh_config_addr;
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int eeh_capable; /* from firmware */
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int eeh_check_count; /* # times driver ignored error */
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int eeh_freeze_count; /* # times this device froze up. */
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int eeh_is_bridge; /* device is pci-to-pci bridge */
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int pci_ext_config_space; /* for pci devices */
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struct pci_controller *phb; /* for pci devices */
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struct iommu_table *iommu_table; /* for phb's or bridges */
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struct pci_dev *pcidev; /* back-pointer to the pci device */
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struct device_node *node; /* back-pointer to the device_node */
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u32 config_space[16]; /* saved PCI config space */
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};
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/* Get the pointer to a device_node's pci_dn */
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#define PCI_DN(dn) ((struct pci_dn *) (dn)->data)
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struct device_node *fetch_dev_dn(struct pci_dev *dev);
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/* Get a device_node from a pci_dev. This code must be fast except
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* in the case where the sysdata is incorrect and needs to be fixed
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* up (this will only happen once).
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* In this case the sysdata will have been inherited from a PCI host
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* bridge or a PCI-PCI bridge further up the tree, so it will point
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* to a valid struct pci_dn, just not the one we want.
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*/
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static inline struct device_node *pci_device_to_OF_node(struct pci_dev *dev)
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{
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struct device_node *dn = dev->sysdata;
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struct pci_dn *pdn = dn->data;
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if (pdn && pdn->devfn == dev->devfn && pdn->busno == dev->bus->number)
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return dn; /* fast path. sysdata is good */
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return fetch_dev_dn(dev);
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}
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static inline struct device_node *pci_bus_to_OF_node(struct pci_bus *bus)
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{
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if (bus->self)
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return pci_device_to_OF_node(bus->self);
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else
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return bus->sysdata; /* Must be root bus (PHB) */
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}
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extern void pci_process_bridge_OF_ranges(struct pci_controller *hose,
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struct device_node *dev);
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extern int pcibios_remove_root_bus(struct pci_controller *phb);
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extern void phbs_remap_io(void);
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static inline struct pci_controller *pci_bus_to_host(struct pci_bus *bus)
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{
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struct device_node *busdn = bus->sysdata;
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BUG_ON(busdn == NULL);
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return PCI_DN(busdn)->phb;
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}
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/* Return values for ppc_md.pci_probe_mode function */
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#define PCI_PROBE_NONE -1 /* Don't look at this bus at all */
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#define PCI_PROBE_NORMAL 0 /* Do normal PCI probing */
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#define PCI_PROBE_DEVTREE 1 /* Instantiate from device tree */
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#endif
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#endif /* __KERNEL__ */
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